Sausages and other formed meat products such as bologna, frankfurters, vienna sausages, and the like are typically made by extruding a proteinaceous meat emulsion or batter into an artificial casing of the desired size and shape and then cooking the batter within the casing. Thereafter, the casing is peeled from the meat product and discarded. Once the casing has been removed, the shaped meat product can be cut into predetermined lengths, placed in suitable containers, and then heated to cook and sterilize the product.
In order to form and process sausages and the like without the need to use casings with their additional costs and problem of disposing of the used casings, various devices and methods for making casingless sausages have been proposed. Among these is the apparatus disclosed in U.S. Pat. Nos. 5,056,425 and 5,118,519 to Mally. The Mally patents disclose apparatus which ejects partially shaped products onto a conveyor assembly. According to the patents, batter is pumped into a molding tube, and a treating assembly is formed as a continuation of the molding tube. The treating assembly functions to introduce treating fluid, typically a food grade acid solution, which causes a proteinaceous skin to form about the batter. A piston or ram mechanism then causes the batter with proteinaceous skin to be deposited onto a conveyor belt. The conveyor belt then continues into a cooking apparatus. Once cooked, the product is canned.
U.S. Pat. No. 3,885,053 to Townsend also discloses a process of forming a skin on an extruded meat emulsion by applying an acid to the surface of the emulsion as the extrusion proceeds. The Townsend patent relies on the use of sintered metal to apply the acid.
The present invention relates to apparatus and methods for forming a proteinaceous emulsion or batter into shaped food products such as sausages without the use of a casing. A supply of suitable proteinaceous emulsion is provided and such emulsion is conveyed under pressure into an elongated hollow stuffing tube to form a continuous length of shaped emulsion. Thereafter the shaped emulsion is directed into a molding tube which is slideably mounted about the stuffing tube. As the emulsion enters the molding tube, the pressure of the emulsion causes the molding tube to move away from the stuffing tube.
A treating fluid, such as a diluted food grade acid, is directed to the interior surface of the molding tube at about the point where the emulsion first enters the molding tube. The treating fluid is directed to the interior of the molding tube in such a manner that the interior of the molding tube is continuously wetted by the treating fluid as the molding tube moves relative to the stuffing tube. This ensures that the entire surface of the shaped emulsion is contacted by the treating fluid thereby forming a proteinaceous skin about the shaped emulsion.
After the molding tube is filled with the emulsion, it is separated from the stuffing tube, subjected to a heat treatment, and a length of formed sausage is removed from the molding tube and subjected to further processing.